WINSTON-SALEM, N.C. (Reuters) - A North Carolina judge on Friday temporarily blocked a state law hours after incoming Democratic Governor Roy Cooper sued to void Republican-backed legislation lessening his control over state and county elections boards, local media reported.

Cooper's transition team described the measure, which would have abolished the current state elections board on Sunday, when he will be sworn in during a private ceremony, as "unconstitutional legislative overreach."

The law, enacted by the state's Republican-dominated legislature during a special session this month, calls for the governor and legislature to appoint four members each to a new board evenly split between Republicans and Democrats. Previously, governors appointed a majority of members.

The measure also replaces three-member county elections boards, where the sitting governor's party had the majority, with four-member boards made up of two Republicans and two Democrats each.

A temporary restraining order issued by a Wake County Superior Court judge will stop the law from taking effect on Sunday, WRAL.com reported.

Cooper's lawsuit argues that the changes violate the state constitution's separation of powers requirements by shifting control from the executive agency responsible for administering election laws to legislators, according to media reports.

The law was among a series of measures approved during a special session in mid-December to curtail Cooper's executive authority before he succeeds outgoing Republican Governor Pat McCrory.

"This complex new law passed in just two days by the Republican legislature is unconstitutional and anything but bipartisan," Cooper said in a statement. "A tie on a partisan vote would accomplish what many Republicans want: making it harder for North Carolinians to vote."

McCrory, who trailed Cooper by about 10,000 votes when he conceded the race nearly four weeks after the Nov. 8 election, and other Republican leaders have argued the new elections law would help ensure a fair voting process.

Senate leader Phil Berger on Friday criticized Cooper's legal action.

"Roy Cooper’s effort to stop the creation of a bipartisan board with an equal number of Democrats and Republicans to enforce elections and ethics laws may serve his desire to preserve his own political power, but it does not serve the best interests of our state," Berger said in a statement.